1. Field of Endeavor
The present disclosure relates to an apparatus for controlling speed in induction motor, and more particularly to an apparatus for controlling speed in an induction motor for use in a continuous processing system.
2. Background
This section provides background information related to the present disclosure which is not necessarily prior art.
Generally, in a production line manufacturing continuous products in a steel, paper, textile and film industries, several motors are employed to simultaneously drive a plurality of rollers. Control of rollers for continuous processing is intended to constantly maintain a line speed of a production line and to constantly maintain tension applied to materials. In a case an excessive tension is generated due to speed deviation in rollers, materials may be fractured or broken.
Thus, in a case an upper level controller in a general continuous processing system calculates a diameter of a material in response to a line speed command and a command torque of a motor, which is then transferred to an inverter, the inverter drives a motor in response to the command torque.
In the continuous processing system thus described, a loadcell of tension sensor and a dancer of position sensor are utilized, in a case the inverter is supplied with a line speed and a reference tension, the system of which may be appropriately employed in a product requiring precision or accuracy.
However, there is no means to maintain a tension for materials, resulting in meandering in the continuous processing line, in a case the loadcell and dancer are not used in a system processing general wire rods.
Accordingly, there is a need of constantly maintaining a tension for materials and preventing meandering in a continuous processing line.